Infants and toddlers often exhibit the dangerous habit of placing small items into their mouths. If such an object is small enough, it may be accidentally swallowed by the child or inhaled into his or her windpipe. If a foreign object becomes lodged in a child's trachea, a life-threatening emergency can result. To avoid such emergencies, objects compressible to or smaller than the maximum diameter of an average child's windpipe should be kept out of reach of the child. Research has revealed that the average human trachea is approximately 1" in diameter. Accordingly, for utmost safety, items smaller than or compressible to about an inch should be inaccessible to a small child. This size may be reduced somewhat for infants and very young children having small, underdeveloped trachea. To date no products are available for quickly and reliably testing these items before they are placed within a child's reach.